Socket of pipe coupling



FIG. 1 is a perspective view of a socket of pipe coupling when seen from the top and left side of the rear, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side elevational view thereof;

FIG. 7 is a right side elevational view thereof; and,

FIG. 8 is a centrally vertically sectioned front view thereof. 

The ornamental design for a socket of pipe coupling, as shown in the drawings and described above. 